The idea for this tree my girlfriend and I got about one month before
Christmas after watching some interesting videos about lamps out of paper tubes. We thought instead of buying a tree we build one from from scratch which will also last more than one Christmas. Because a normal tree would be a bit boring we got the idea to add lights which should be PWM controlled from an microcontroller and make them controllable from the computer to program animation to some songs. So we started building and just finished just on time before Christmas.

Supplies

newspaper or other type of paper
fairy light LEDs (aproximatly 25m for 0,7m huge tree)
5050 RGB LED strips (5 Segments)
spray paint (white and metalic green)
hot glue
wood glue
additional decoration of your choice

Step 1: Build of the Tree

The tree is build from newspaper tubes.
For a tree as huge as this one you need approximately 200 tubes. You get 6 tubes from one double sided newspaper page. Therefore the page is cut into 6 stripes with a with of 10cm. After you cut the strips you can roll them with the help of a small bamboo stick to tubes. The end is glued with wood glue, so that the tube holds together (we are not the creators of the video).

To start with the build of the tree, you do not have to make all the tubes at once, you can also make them step by step. For the base we decided not to use a scare shape as shown in many videos on youtube, but instead use a pentagonal shape. The process is the same as with a square base so we do not describe it in particular, instead you can take the following video as an reference (we are not the creators of the video).

Step 2: Decoration of the Tree

After the folding of the tree is
finished, it gets painted. For Christmas we decided to paint it a metallic green. For that the tree is first sprayed with white paint because the green we used was very transparent. After the first coat of white it is painted green.

Now we waited till the tree was completely dry and started adding the LEDs. The LED were attached individually with gold colored hot glue.

At the edges of the base RGB LED stripes are added. And the cables are added. At the end you have 5 individual controllable LED spirals and 5 LED stripes.

Step 3: Electronics

The control electronic consists of 4
components. Five Padauk microcontrollers (PFS154) have the task to generate the PWM signals for the power electronics. The power electronics consists of small SOT-23 n-channel mosfets, which power the LEDs. The main microcontroller is a ATmega8a, which controls the animations. The Padauk uC are connected to the ATmega8a through one synchronous, serial bus. The different animations can be controlled over UART. To connect USB directly to the PCB a CH340T is used to convert USB to UART. After the schematic is drawn und the PCB was designed, it was ordered at JLCPCB.

Step 4: Software

For the complete project tree different
software are programmed. The software for the PFS154, the ATmega8a and the control GUI for the computer.

The PFS154 software has only one task. It decodes the synchronous bus data (adress and PWM value) and configurates the four PWM channels per uC. Each PWM channel has a different adress.

The ATmega8a has the task to generate the animations and send the PWM values through the synchronous bus. The user can chose the animations for the RGB stripes and the LED spirals individually. For the RGB stripes the are the individual control of each of the five stripes, the pulse and rotations of two or three different colors. The animations for the LED Spirals are similar. There is also a individual control, a pulse animation and two different rotation animations (single rotation: only one LED spiral is on; fading rotation: smooth rotation with different brightnesses).

These animations can be configurated through UART. The animation and the different parameters can be configurated this way.

The GUI is programmed with visual studio in C# and allows manual and automatic control of the animation. In the manual control each animation can be chosen, configurated and send to the ATmega8a. The automatic control allows the use to set animations to timestamps (1ms resolution). This way a song can be played with the software and the animations are send automatic as configurated.